1. Symbolic Logic and Mechanical Theorem-Proving;Chang,1973
2. Path systems and language recognition;Cook;Proc. Second ACM Symp. on Theory of Computing,1970
3. The complexity of theorem-proving procedures;Cook;Proc. Third ACM Symp. on Theory of Computing,1971
4. An observation on time-storage trade-off;Cook;J. Comput. System Sci.,1974
5. A combinatorial problem which is complete in polynomial space;Even;Proc. Seventh ACM Symp. on Theory of Computing,1975